Joyce,
I am sorry, the only information I know about Muchamiel is listed here (I know, this is not a lot, but that's all I have at this time) -
http://tatianastomatobase.com/wiki/Muchamiel
As this is not a Czech variety, I would doubt there is lots of info about it in the Czech seed bank.
Tatiana
EDITED TO ADD: Fred created a new thread (
http://www.tomatoville.com/showthread.php?t=30444) to address the question about Muchamiel. Thank you Fred!